`int(xe^x)/(1+x^2)dx`

Explanation

`int(xe^x)/(1+x^2)dx=inte^x{1/(1+x)-1/(1+x)^2}dx`
[Integrating by parts taking `1/(1+x)` as first
and `e^x` as second function.]
=`1/(1+x).e^x-int(-1)/(1+x)^2e^xdx-inte^x.1/(1+x)^2dx+C`
=`1/(1+x)e^x+inte^x/(1+x)^2dx-inte^x/(1+x)^2dx+C`
=`e^x/(1+x)+C`